So the first question would be, what are you looking to build the deck for? Casual play? Potentially competitive play? Is there a format you're looking to play? Most of the deck appears to be standard, but then you have items from the original Ravnica block and other older sets that result in it being a legacy deck.
The reason I ask is because each level of play and format carries different expectations and different requirements. Casual decks can afford to have 1x of most cards like you do as people typically aren't as ruthless in casual play and are just looking to have a good time. Competitive play would require a lot more attention to the decklist to ensure that you have higher amounts of consistency and more powerful combos.
That aside, if you're looking to shave value off of the deck, the two most obvious places would be Serra Ascendant and Sphinx's Revelation as those two cards alone are almost $30. Personally, I would take out the ascendant as its value is inflated by EDH and legacy players far more than anyone else. It doesn't really fit into what you appear to be doing with the deck and aside a few cards, you're unlikely to reach the 30 life to make it a real threat anyway. That would bring the deck value down to $77.70. If you were to drop the Revelation, you're already down to $60.06.
If you were to keep the revelation, you'll end up having to drop Grand Arbiter Augustin IV and a bunch of other $1-3 dollar cards (most notably Glacial Fortress).
Ultimately it's up to you what stays and goes, but if you're looking to keep it under $60, those two will definitely get you there.